Protective Role of Heme Oxygenase in Ischemic Brain

血红素加氧酶在缺血性脑中的保护作用

• 批准号: 6529669
• 负责人: Mahin D. Maines
• 金额: $ 23.93万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6529669
• 关键词: apoptosis; bilirubin; binding proteins; blood brain barrier; blood vessels; brain edema; cerebral hemorrhage; cerebral ischemia /hypoxia; cerebrospinal fluid; colony stimulating factor; cyclic GMP; enzyme activity; enzyme induction /repression; ferritin; gene therapy; genetically modified animals; glutamates; heme oxygenase; hemoglobin; laboratory mouse; neurogenetics; neurons; oxidative stress; stroke; stroke therapy; transfection /expression vector; transient ischemic attack; vasospasm

A complication of stroke is cerebral hemorrhage. The heme oxygenase (HO) system, which plays a key role in cellular defense mechanisms, catalyses oxidation of hemoglobin heme to biologically active molecules: bile pigments and CO. We have identified two active forms of the enzyme: HO-1 and HO-2. HO-2 is a hemoprotein and may function as a "sink" for NO, an effector molecule in inflammation and immune response. We have developed transgenic (Tg) mice that overexpress HO-1 or HO-2. HO-1 Tg mice brain, when compared with nonTg mice, show increased neuronal cGMP levels and expression of HO-1 in the lining of blood vessels. And, after pMCAo, they show decreases in brain stroke volume and in lipid peroxidation. Also, Tg mice neurons are resistant to H2O2 and glutamate toxicity. Initial studies with the HO-2 Tg line show increase in neuronal HO-2 expression and decrease in brain lipid peroxidation. To date, no data are available on the effect of HO-2 overexpression on the outcome of stroke. Deletion of the gene, however, exacerbates such injury. Also, the effect of HO-1 gene transfer on CNS injury has not been examined. Although, upregulation of HO-1 gene expression, using adenovirus (Ad)-mediated gene transfer, is known to protect against oxidative stress-mediated systemic tissue injury. The overall objective of this proposal is to further explore the role of HO isozymes in neuronal protection against stroke and cerebral hemorrhage. Specific aims are: 1) Using the HO-1 and HO-2 Tg mice to investigate the effect of HO gene overexpression on the outcome of transient focal ischemia (tMCAo), and on subarachnoid hemorrhage (SAH) caused by injection of lysed blood into the subarachnoid space. The tMCAo model will be evaluated for progression of ischemic injury and markers of stress: lipid peroxidation and redox available iron; also, for heme and bilirubin levels. The SAH model will be evaluated for vasospasm and necrotic/ apoptotic cell death. 2) To evaluate in the above models the potential therapeutic benefits of Ad-HO-1 and Ad-HO-2 gene transfer in stroke and cerebral hemorrhage. Genes will be delivered by CSF or by intracarotid route and the same indeces will be evaluated.

中风的并发症是脑出血。 血红素氧化酶（HO）系统在细胞防御机制中起关键作用，将血红蛋白血红素的氧化催化为生物活性分子：胆汁颜料和CO。我们已经鉴定出酶的两种活性形式：HO-1和HO-2。 HO-2是一种血蛋白，可以用作否，在炎症和免疫反应中的效应分子。 我们已经开发了过表达HO-1或HO-2的转基因（TG）小鼠。 与NONTG小鼠相比，HO-1 TG小鼠的大脑显示出神经元CGMP水平增加，而HO-1在血管内膜中的表达增加。 并且，在PMCAO之后，它们显示出脑冲程体积和脂质过氧化的减少。 同样，TG小鼠神经元对H2O2和谷氨酸毒性具有抗性。 HO-2 TG系的初步研究表明，神经元HO-2表达的增加和脑脂质过氧化的降低。 迄今为止，尚无关于HO-2过表达对中风结果的影响的数据。 但是，该基因的缺失加剧了这种损伤。同样，尚未检查HO-1基因转移对中枢神经系统损伤的影响。 尽管使用腺病毒（AD）介导的基因转移的HO-1基因表达的上调已知可以预防氧化应激介导的全身组织损伤。 该提案的总体目的是进一步探讨HoHoshemes在神经元保护抗中风和脑出血中的作用。 具体目的是：1）使用HO-1和HO-2 TG小鼠研究HO基因过表达对瞬时局灶性缺血结果（TMCAO）的影响，以及对通过向亚蛛网膜下腔空间注射裂解的血液引起的亚蛛网膜下腔出血（SAH）。 将评估TMCAO模型的缺血性损伤和压力标记：脂质过氧化和氧化还原的铁；此外，对于血红素和胆红素水平。 SAH模型将用于血管痉挛和坏死/凋亡细胞死亡。 2）在上述模型中评估中风和脑出血中AD-HO-1和AD-HO-2基因转移的潜在治疗益处。 基因将由CSF或核内途径传递，并评估相同的indeces。